A simple electrocardiographic predictor of the outcome of patients with acute myocardial infarction treated with a thrombolytic agent. A Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto Miocardico (GISSI-2)-Derived Analysis

Fibrinolytic Therapy in Patients with Acute ST-elevation Myocardial Infarction

Fibrinolytic agents provide an important alternative therapeutic strategy in individuals presenting with ST-elevation myocardial infarction (STEMI). Ultimately, primary percutaneous coronary intervention (PCI) is the preferred reperfusion strategy for most patients with STEMI, including elderly patients and patients with coronavirus disease 2019 (COVID-19) infection. Fibrinolytic therapy should always be considered when timely primary PCI cannot be delivered appropriately. Clinicians should promptly recognize the signs of fibrinolytic therapy failure and consider rescue PCI. When fibrinolytics are used, coronary angiography and revascularization should not be conducted within the initial 3 hours after fibrinolytic administration.

Does pre-angiography Total ST-segment resolution reliably predict spontaneous reperfusion of the infarct-related artery in patients with acute myocardial infarction?

BACKGROUND

ST resolution (STR) after AMI is a non-invasive indicator of IRA reperfusion. We investigated whether pre-angiography STR predicted spontaneous IRA reperfusion in STEMI patients.

METHOD

Patients with STEMI undergoing primary PCI were recruited. Standard 12-lead ECG tracings were recorded at first medical contact, immediately prior to arterial puncture and 60 min after PCI. STR was classified as total (≥70%; group I), partial (≥30 and < 70%; group II) or none (< 30%; group III). Patients were followed up for 1-year.

RESULTS

The final analysis included 349 patients (n = 77, 160 and 112 for groups I, II and III, respectively). Compared with groups I/II, pre-procedural TIMI flow in group III was less frequently grades 2 or 3 (P < 0.001). Pre-PCI STR ≥70% was an independent predictor of pre-PCI TIMI-3 flow (OR: 2.8; P < 0.001). Pre-PCI STR < 30% was independently associated with pre-PCI TIMI flow 0-2 (OR: 3.1; P < 0.001). STR = 35.55% seems to be an optimal cut off for pre-procedural TIMI-3 flow prediction with sensitivity 0.943, specificity 0.456, Youden index 0.399, P = 0.027. STR prior to PCI was inversely correlated with 1-year combined CV events rate. STR > 70% may predict a better clinical outcome.

CONCLUSIONS

Assessment of STR could potentially be used to stratify risk in patients with STEMI before PCI.

Role of no reflow and microvascular obstruction in the prognostic stratification of STEMI patients

Effective reperfusion of ischemic myocardium is the final aim of both pharmacological and mechanical reperfusive strategies in patients with ST-segment elevation myocardial infarction. More effective reperfusion is related to better prognosis. In contrast, ineffective reperfusion (no reflow) has been showed to be related to an increased rate of adverse events in the flow-up. Several techniques can be used to assess the effectiveness of reperfusion, and the evolved over the last decades according to the treatment methods but also to technological advancements. ST-segment resolution represented the only way to assess reperfusion in the era of pharmacological treatment. Later, angiographic assessment became the gold standard to assess reperfusion after primary percutaneous coronary intervention. In the last years, cardiac magnetic resonance showed improved accuracy and prognostic stratification ability compared with angiography. However, in clinical practice, coronary angiographic still remains the more widely used assessment technique for no reflow.

Integrated ST Segment Elevation Scores and In-hospital Mortality in STEMI Patients Undergoing Primary PCI

The objective of this study was to study the integrated score of ST-segment resolution (ISSTE) and in-hospital death in patients undergoing primary percutaneous intervention (pPCI) for ST-segment elevation myocardial infarction (STEMI).

Material and Methods: This prospective study included 586 consecutive patients admitted with STEMI to the Cardiology Clinic of the County Emergency Clinical Hospital of Tîrgu Mureș, between January 1st, 2013 and December 31, 2014, who underwent pPCI in less than twelve hours after the onset of symptoms. Clinical and demographic data were analyzed in 539 (91.9%) survivors (Group 1) and 47 (8.1%) nonsurvivors (Group 2). The Integrated Score of ST elevation (ISSTE) was calculated by summing the amplitude of the ST segment elevation in all the 12 leads, before and at 2 hours after revascularization.

Results: The ISSTE score calculated at baseline, immediately before the primary percutaneous coronary intervention, was significantly higher in Group 2 as compared to Group 1 (13.9 ± 1.2 vs. 11.0 ± 0.2, p = 0.026). At the same time, the ISSTE score calculated at 2 hours after the coronary intervention was significantly higher for patients in Group 2 (7.36 ± 1.12 vs. 2.9 ± 0.1, p <0.0001). Analysis of the dynamics of the ISSTE score indicated that patients who survived presented a more expressed reduction in the ISSTE score following pPCI, as compared to those who subsequently died (73.5% reduction in Group 1 compared to 47.2% reduction in Group 2, p <0.0001). In-hospital mortality was significantly higher in the group of patients with >50% reduction in the ISSTE score. The in-hospital death rate was 5.4% in patients with >50% reduction in the ISSTE score, compared to 19.4% for those who presented less than 50% reduction in the ISSTE score following pPCI (p <0.0001). The rate of successful reperfusion rate, expressed by the reduction in ISSTE score, was 83.8% in Group 1, compared to 55.3% in Group 2 (p <0.0001), indicating that the absence of an efficient reperfusion after pPCI is associated with a higher mortality in STEMI patients, and could be evaluated using regression of the ISSTE score, which proved to be directly associated with mortality.

Conclusion: The ISSTE score is shown to be an effective ECG-derived marker of myocardial damage in STEMI patients. A high ISSTE score is associated with higher mortality, while a reduction in the ISSTE score after pPCI may indicate an efficient reperfusion and a decrease in mortality in the first days after infarction.

Mean platelet volume is a predictor of ST resolution following thrombolysis in acute ST elevation myocardial infarction

BACKGROUND

Larger mean platelets volumes (MPV) are thrombogenic and frequently seen after ST-segment elevation myocardial infarction (STEMI). This study aimed to examine the association of MPV and resolution of ST-segment after thrombolysis in STEMI patients as and its impact on clinical outcome.

METHODS

Patients presenting to the emergency department with the diagnosis of first STEMI and were referred to thrombolysis were screened. Patients with ≥50% ST-segment resolution (STR) 90minutes after thrombolysis were assigned as "Responder" and those with <50% STR were assigned as "Non-Responders". Demographic, clinical comorbidities and risk factor were recorded along with and angiographic data. In-hospital occurrence of major adverse cardiac events (MACE), including acute heart failure (AHF), reinfarction and death were investigated. Additionally, the patients were followed for 6 additional months after their discharge from the hospital.

RESULTS

STR≥50% was seen in 60.2% of patients after thrombolysis. Responders had significantly lower MPV (P=0.001) and the critical MPV values were 8.0 femtoliter (fL) and 8.2fL in predicting STR and MACE. Patients with MPV ≥8.2fL had lower probability of STR and higher rates of AHF (P<0.001), and MACE (P=0.001) compared to the patients with lower platelet volume. In multivariate regression, MPV was an independent predictor of STR (P<0.001) as well as MACE (HR=4.8, 95% CI of 1.8-12.4; P=0.001). Triple vessel disease was another independent factor that predicted MACE.

CONCLUSION

Higher MPV's at admission were associated with lower STR and higher occurrence of major adverse cardiac events in patients receiving thrombolytic therapy for first time STEMI.

Pre-angiography total ST-segment resolution is not a reliable predictor of an open infarct-related artery

BACKGROUND

While the cutoffs of predictive value for ST-segment elevations resolution (STSR) following thrombolysis and/or primary PCI were well documented, the impact of pre-angiography STSR has not been established yet.

OBJECTIVES

The aim of this study is to assess prognostic utility of pre-angiography STSR to predict pre-procedural TIMI flow in the infarct-related artery (IRA) and infarct size in STEMI patients undergoing primary PCI.

METHODS

A prospective study was performed, including 310 patients, admitted within 12h of symptom onset and who underwent primary PCI. ST-segment elevations were measured in: (1) qualifying ECG, (2) ECG before angiography, and (3) ECG post PCI. STSR was defined as: total (≥70%), partial (between 70% and 30%) and none (<30%). Relationships between pre-angiography STSR, initial TIMI flow and troponin T level (TnT) were analyzed.

RESULTS

Pre-angiography STSR correlated with initial TIMI flow in the IRA (rS=0.619; p<0.001). Pre-angiography total STSR was observed in 23.2% patients. It was noted in 79.2% of patients with pre-procedural TIMI flow ≥2 and in 20.8% with TIMI flow ≤1 (p<0.001). Although the sensitivity of pre-angiography total STSR to detect pre-procedural TIMI flow ≥2 was 93%, its specificity was only 56% and the likelihood ratio was 2.1. Pre-angiography total STSR was associated with lower peak TnT level (2.2±2.5ng/ml vs. 6.4±5.0ng/ml, p<0.0001) when compared to the remaining patients.

CONCLUSIONS

1. Pre-angiography STSR correlates with preprocedural TIMI flow. 2. The sensitivity of pre-angiography total STSR in detection of pre-procedural TIMI flow ≥2 is high, but low specificity of only 56% makes it an unreliable predictor of an open IRA.

Hypertension and acute myocardial infarction: an overview

History of hypertension is a frequent finding in patients with acute myocardial infarction (AMI) and its recurring association with female sex, diabetes, older age, less frequent smoking and more frequent vascular comorbidities composes a risk profile quite distinctive from the normotensive ischemic counterpart.Antecedent hypertension associates with higher rates of death and morbid events both during the early and long-term course of AMI, particularly if complicated by left ventricular dysfunction and/or congestive heart failure. Renin-angiotensin-aldosterone system blockade, through either angiotensin-converting enzyme inhibition, angiotensin II receptor blockade or aldosterone antagonism, exerts particular benefits in that high-risk hypertensive subgroup.In contrast to the negative implications carried by antecedent hypertension, higher systolic pressure at the onset of chest pain associates with lower mortality within 1 year from coronary occlusion, whereas increased blood pressure recorded after hemodynamic stabilization from the acute ischemic event bears inconsistent relationships with recurring coronary events in the long-term follow-up.Whether antihypertensive treatment in post-AMI hypertensive patients prevents ischemic relapses is uncertain. As a matter of fact, excessive diastolic pressure drops may jeopardize coronary perfusion and predispose to new acute coronary events, although the precise cause-effect mechanisms underlying this phenomenon need further evaluation.

The impact of hypertension on patients with acute coronary syndromes

Arterial chronic hypertension (HTN) is a well-known cardiovascular risk factor for development of atherosclerosis. In order to explain the relation between HTN and acute coronary syndromes the following factors should be considered: (1) risk factors are shared by the diseases, such as genetic risk, insulin resistance, sympathetic hyperactivity, and vasoactive substances (i.e., angiotensin II); (2) hypertension is associated with the development of atherosclerosis (which in turn contributes to progression of myocardial infarction). From all the registries and the data available up to now, hypertensive patients with ACS are more likely to be older, female, of nonwhite ethnicity, and having a higher prevalence of comorbidities. Data on the prognostic role of a preexisting hypertensive state in ACS patients are so far contrasting. The aim of the present paper is to focus on hypertensive patients with ACS, in order to better elucidate whether these patients are at higher risk and deserve a tailored approach for management and followup.

Does ST resolution achieved via different reperfusion strategies (fibrinolysis vs percutaneous coronary intervention) have different prognostic meaning in ST-elevation myocardial infarction? A systematic review

OBJECTIVE

We perform a systematic review to discern if ST resolution achieved via percutaneous coronary intervention (PCI) has a different meaning to that achieved via fibrinolysis.

BACKGROUND

Resolution of ST-segment elevation in acute myocardial infarction has been widely used as a surrogate for treatment success. A recent randomized study suggested that after primary PCI, the prognostic significance of ST resolution may have been overemphasized.

METHODS

Using the MEDLINE, COCHRANE, EMBASE, and PUBMED databases to search for the relevant papers, we analyze the data with a new ST-resolution score. ST-resolution groups of <30%, 30% to < 70%, and ≥ 70% are given scores of 1, 2, and 3 respectively, whereas ST-resolution groups reported as < 50% are scored as 1.5, and ≥ 50% scored as 2.5.

RESULTS

We identify 18 fibrinolysis cohorts (32,341 patients) and 5 PCI cohorts (1,913 patients). The mean ST-resolution score weighted for the number of patients in each cohort is 1.87 ± 0.15 for PCI and 1.66 ± 0.20 for fibrinolysis (P < .001). The raw combined 30-day mortality is 4.9% with fibrinolysis and 4.3% with PCI (P = .452 by Poisson regression). There is a linear relationship with lower 30-day mortality associated with higher ST-resolution score. The regression line for the PCI cohorts almost overlaps with that from the fibrinolysis cohorts. On multivariate regression, only ST-resolution score is significant in predicting 30-day mortality. When tested, the interaction term (treatment group × ST resolution score) is never a significant predictor (P > .25 in all models).

CONCLUSION

ST resolution after different reperfusion therapies has similar prognostic meaning.

Extent of ST-segment resolution after fibrinolysis adds improved risk stratification to clinical risk score for ST-segment elevation myocardial infarction

BACKGROUND

The TIMI risk score (TRS) for ST-segment elevation myocardial infarction (STEMI) is a convenient validated clinical risk score for predicting mortality. Although not part of the risk score, ST-segment resolution (STRes) may provide a simple method of risk stratification based on the response to reperfusion. We sought to determine whether STRes provides incremental risk stratification to the TIMI risk score.

METHODS

The Clopidogrel as Adjunctive Reperfusion Therapy--Thrombolysis in Myocardial Infraction (CLARITY-TIMI 28) trial randomized STEMI patients receiving fibrinolysis to clopidogrel or placebo. A total of 2,340 patients had electrocardiograms (ECGs) valid to calculate STRes at 90 minutes, which was defined as complete (>70%), partial (30%-70%), or no resolution (30%). TRS was defined as low (0-2), medium (3-4), and high (> or =5). Clinical follow-up was through 30 days. Results were validated in 2,743 patients from the ExTRACT-TIMI 25 study.

RESULTS

The degree of STRes at 90 minutes after fibrinolysis correlated in a stepwise fashion with death or heart failure (5.1% complete STRes, 8.9% partial STRes, 13.4% no STRes, P < .001). Furthermore, the degree of STRes provided a consistent and significant gradient of risk across all risk score categories (low, medium, or high) and significantly improved the discriminatory ability of TIMI risk score to predict death or heart failure (c-statistic 0.69 for TIMI risk score alone and 0.74 with STRes added to the model, P < .001). With the inclusion of STRes to the TIMI risk score, 913 patients (39%) were reclassified to higher or lower risk groups, and the net reclassification improvement (NRI) was highly significant (P < .001). In the ExTRACT-TIMI 25 trial, addition of the STRes improved also the c-statistic (P = .012) and NRI (P < .001).

CONCLUSIONS

The extent of STRes based on routinely obtained ECGs is an independent predictor of death and heart failure when used together with the TIMI risk score and significantly improves the ability to risk stratify patients after fibrinolysis.

Clinical effects of hypertension on the mortality of patients with acute myocardial infarction

The incidence of ischemic heart disease has been increased rapidly in Korea. However, the clinical effects of antecedent hypertension on acute myocardial infarction have not been identified. We assessed the relationship between antecedent hypertension and clinical outcomes in 7,784 patients with acute myocardial infarction in the Korea Acute Myocardial Infarction Registry during one-year follow-up. Diabetes mellitus, hyperlipidemia, cerebrovascular disease, heart failure, and peripheral artery disease were more prevalent in hypertensives (n=3,775) than nonhypertensives (n=4,009). During hospitalization, hypertensive patients suffered from acute renal failure, shock, and cerebrovascular event more frequently than in nonhypertensives. During follow-up of one-year, the incidence of major adverse cardiac events was higher in hypertensives. In multi-variate adjustment, old age, Killip class > or =III, left ventricular ejection fraction <45%, systolic blood pressure <90 mmHg on admission, post procedural TIMI flow grade < or =2, female sex, and history of hypertension were independent predictors for in-hospital mortality. However antecedent hypertension was not significantly associated with one-year mortality. Hypertension at the time of acute myocardial infarction is associated with an increased rate of in-hospital mortality.

Time to treatment and ST-segment resolution in high-risk patients with acute myocardial infarction transferred from community hospitals for coronary angioplasty after pharmacological treatment

OBJECTIVE

To evaluate the impact of symptom-onset-to-balloon delay on ST-segment resolution (STR) in patients with acute myocardial infarction transferred from community hospitals for angioplasty after pharmacological treatment. The study design was prospective, single centre registry.

METHODS

Between October 2000 and December 2003, 330 consecutive patients aged < or =75 years with high-risk myocardial infarction were considered; 193 patients underwent primary percutaneous coronary intervention (PCI) (group P), whereas 137 patients were given pharmacological therapy and were immediately transferred to the hospital with PCI facilities (group F).

RESULTS

Compared with group P, group F showed a longer time to treatment (253 +/- 136 vs. 195 +/- 141 min; P < 0.0001) and a higher percentage of Thrombolysis In Myocardial Infarction flow grade 2-3 at pre-PCI angiography (107 [78.1%] vs. 48 [24.8%]; P < 0.0001). The rate of STR > or =70% was similar in groups P and F (121 [62.7%] vs. 94 [68.6%]; P = 0.41). Even after accounting for baseline variables, STR <70% was not significantly related to the transfer strategy (adjusted hazard ratio 0.94, 95% confidence interval 0.94-1.77; P = 0.8). Patients with incomplete STR showed a higher six-month mortality compared with patients with complete STR (10 [8.85%] vs. 6 [2.76%]; P = 0.027).

CONCLUSIONS

The STR index predicts survival in patients with ST-elevation myocardial infarction treated with angioplasty either directly or after pharmacological treatment and hospital transfer. Pharmacological facilitation seems to be able to counterbalance the negative consequences of the transfer-related time delay on myocardial reperfusion as evaluated by the STR index.

Baseline glucose and left ventricular remodeling after acute myocardial infarction

In patients with acute myocardial infarction (AMI), the mechanisms behind the increased mortality related to glucose levels (GL) are poorly understood. The main purpose of this study is to analyze the relationship between baseline glucose and left ventricular enlargement (LVE). We analyzed 52 patients with a first ST-elevation AMI <24 h of evolution. Glucose levels were obtained upon admission (median time, 3 h after the beginning of chest pain). The median GL was 123.5 mg/dl, and patients above this limit were considered hyperglycemic (n=26). Left ventricular enlargement was analyzed comparing two radionuclide ventriculographies, the first obtained within 4 days post-AMI (median, 55 h) and the second 6 months later (median, 188.5 days), taking into account the difference in the obtained end-systolic volumes. Myocardial reperfusion was evaluated comparing ST resolution between a first ECG done immediately upon hospital arrival with a second ECG performed 2 h after treatment. By univariate analysis, LVE correlated significantly with baseline hyperglycemia (P<.001), failed reperfusion by ECG criteria (P<.001), and no use of ACE inhibitors or AT1 blockers (P=.046) and aspirin (P=.046). A history of previous diabetes did not correlate significantly with LVE at 6 months. In the adjusted model, basal hyperglycemia (P<.001) and failed reperfusion (P=.001) were the only variables independently correlated with LVE. In conclusion, baseline glucose is a powerful and independent predictor of LVE after AMI, which reinforces the importance of a tight glucose control during the initial phase of the disease.

ST variability during the first 4 hours of acute myocardial infarction predicts 1-year mortality

BACKGROUND

Early and complete myocardial reperfusion is the goal when treating a patient with acute myocardial infarction. To achieve this in each individual, an on-line, accurate, easily handled and preferably noninvasive technique to monitor flow alterations is needed. Recurrent ST-segment elevation has been shown to reflect cyclic disturbances in perfusion.

METHODS

We have retrospectively analyzed ST variability in 102 patients with acute myocardial infarction randomized to 100 mg of rt-Pa or placebo. Patients were monitored for 24 hours using vectorcardiography.

RESULTS

Patients alive at one year (86%) had significantly less ST variability during the first four hours: 4.3 versus 7.1 episodes, P = 0.007. Patients having six or more ST episodes showed a 31.3% one-year mortality as compared to no mortality in patients having no ST variability. Furthermore ST variability was reduced by fibrinolysis.

CONCLUSION

Early ST variability detectable in real time is associated with worse outcome.

Thrombus aspiration before primary angioplasty improves myocardial reperfusion in acute myocardial infarction: the DEAR-MI (Dethrombosis to Enhance Acute Reperfusion in Myocardial Infarction) study

OBJECTIVES

This study sought to test the hypothesis that thrombus removal, with a new manual thrombus-aspirating device, before primary percutaneous coronary intervention (PPCI) may improve myocardial reperfusion compared with standard PPCI in patients with ST-segment elevation acute myocardial infarction (STEMI).

BACKGROUND

In STEMI patients, PPCI may cause thrombus dislodgment and impaired microcirculatory reperfusion. Controversial results have been reported with different systems of distal protection or thrombus removal.

METHODS

One-hundred forty-eight consecutive STEMI patients, admitted within 12 h of symptom onset and scheduled for PPCI, were randomly assigned to PPCI (group 1) or manual thrombus aspiration before standard PPCI (group 2). Patients with cardiogenic shock, previous infarction, or thrombolytic therapy were excluded. Primary end points were complete (>70%) ST-segment resolution (STR) and myocardial blush grade (MBG) 3.

RESULTS

Baseline clinical and angiographic characteristics were similar in the 2 groups. Comparing groups 1 and 2: complete STR 50% versus 68% (p < 0.05); MBG-3 44% versus 88% (p < 0.0001); coronary Thrombolysis In Myocardial Infarction (TIMI) flow grade 3 78% versus 89% (p = NS); corrected TIMI frame count 21.5 +/- 12 versus 17.3 +/- 6 (p < 0.01); no reflow 15% versus 3% (p < 0.05); angiographic embolization 19% versus 5% (p < 0.05); direct stenting 24% versus 70% (p < 0.0001); and peak creatine kinase-mass band fraction 910 +/- 128 mug/l versus 790 +/- 132 mug/l (p < 0001). In-hospital clinical events were similar in the 2 groups. After adjusting for confounding factors, multivariate analysis showed thrombus aspiration to be an independent predictor of complete STR and MBG-3.

CONCLUSIONS

Manual thrombus aspiration before PPCI leads to better myocardial reperfusion and is associated with lower creatine kinase mass band fraction release, lower risk of distal embolization, and no reflow compared with standard PPCI. (Thrombus Aspiration Before Standard Primary Angioplasty Improves Myocardial Reperfusion in Acute Myocardial Infarction; http://clinicaltrials.gov/ct/show/NCT00257153).

The 12-lead electrocardiogram as a predictive tool of mortality after acute myocardial infarction: current status in an era of revascularization and reperfusion

Many recently published studies established the admission electrocardiogram as an excellent source of prognostic information in patients presenting with acute myocardial infarction. Using our search criteria, we identified a large number of articles but selected only the most relevant in each category. The best predictors of increased short-term mortality are ventricular tachycardia (odds ratio [OR] 6.1, 95% CI 4.6-8.3), ST-segment deviations (OR 5.1, 95% CI 4.6-8.3), high-degree atrioventricular block (OR 5.1, 95% CI 2.1-11.9), and long QRS duration (OR 4.2, 95% CI 1.8-10.4). For increased long-term mortality, the best predictors were ST-segment depression (OR 5.7, 95% CI 2.8-11.6), ST-segment elevation (OR 3.3, 95% CI 2.1-5.1), and left bundle-branch block (OR 2.8, 95% CI 1.8-4.3). In addition, our review discusses electrocardiographic markers of poor outcome that were not independent risk factors on multivariate analysis, conflicting findings, and knowledge gaps that can help plan future research efforts.

The Role of Clopidogrel in Early and Sustained Arterial Patency After Fibrinolysis for ST-Segment Elevation Myocardial Infarction

OBJECTIVES

This study was designed to determine the relationship between clopidogrel and early ST-segment resolution (STRes) and the interaction of the two with clinical outcomes after fibrinolysis.

BACKGROUND

ST-segment resolution is an early noninvasive marker of coronary reperfusion.

METHODS

The CLARITY-TIMI 28 (Clopidogrel as Adjunctive Reperfusion Therapy-Thrombolysis in Myocardial Infarction 28) trial randomized 3,491 patients with ST-segment elevation myocardial infarction (STEMI) undergoing fibrinolysis to clopidogrel versus placebo. ST-segment resolution was defined as complete (>70%), partial (30% to 70%), or none (<30%).

RESULTS

Electrocardiograms were valid for interpretation in 2,431 patients at 90 min and 2,087 at 180 min. There was no difference in the rate of complete STRes between the clopidogrel and placebo groups at 90 min (38.4% vs. 36.6% at 90 min). When patients were stratified by STRes category, treatment with clopidogrel resulted in greater benefit among those with evidence of early STRes, with greater odds of an open artery at late angiography in patients with partial (odds ratio [OR] 1.4, p = 0.04) or complete (OR 2.0, p < 0.001) STRes, but no improvement in those with no STRes at 90 min (OR 0.89, p = 0.48) (p for interaction = 0.003). Clopidogrel was also associated with a significant reduction in the odds of an in-hospital death or myocardial infarction in patients who achieved partial (OR 0.30, p = 0.003) or complete STRes at 90 min (OR 0.49, p = 0.056), whereas clinical benefit was not apparent in patients who had no STRes (OR 0.98, p = 0.95) (p for interaction = 0.027). By 30 days, the clinical benefit of clopidogrel was predominately seen in patients with complete STRes.

CONCLUSIONS

Clopidogrel appears to improve late coronary patency and clinical outcomes by preventing reocclusion of open arteries rather than by facilitating early reperfusion.

Clinical course of acute myocardial infarction in the hypertensive patient in Eastern Spain: The PRIMVAC registry

OBJECTIVE

The study's objective was to analyze the acute complications and prognosis of acute myocardial infarction (AMI) in hypertensive patients in Spain.

METHOD

Complications and early mortality were recorded among the patients with AMI admitted to the coronary care units of the 17 hospitals in the Valencia Community (Spain) between 1995 and 2000.

RESULTS

A total of 12.071 patients were registered, of whom 46% were hypertensive (5.550 cases). Atrial fibrillation was more frequent in the hypertensive group, whereas ventricular fibrillation was more common among normotensive patients. We found higher mortality rates in the hypertensive group (14.4% vs 12.4%; P<.001). However, after multivariate adjustment, hypertension was not independently associated with mortality (odds ratio: .95; P=.46), and remained independently associated with a lower risk of primary ventricular fibrillation (odds ratio: .83; P<.05).

CONCLUSION

Hypertensive patients do not present comparatively greater mortality during AMI, although primary ventricular fibrillation is less common in such subjects.

Relation of terminal QRS distortion to left ventricular functional recovery and remodeling in acute myocardial infarction treated with primary angioplasty

The association between admission electrocardiogram and 6-month change in left ventricular function and volume was assessed in 200 patients who had acute myocardial infarction that was treated with primary percutaneous coronary intervention. Logistic regression analysis indicated peak creatine phosphokinase-MB, number of Q-wave leads, QRS interval distortion, wall motion score index, and angiographic Thrombolysis In Myocardial Infarction flow grade as predictors of no functional recovery and QRS interval distortion and Thrombolysis In Myocardial Infarction flow grade as predictors of left ventricular remodeling.

Continuous ST-segment monitoring of patients with right bundle branch block and suspicion of acute myocardial Infarction

BACKGROUND

Patients with right bundle branch block comprise 5-9% of all patients with acute myocardial infarction. In spite of this, limited data exist on early diagnosis or the usefulness of continuous electrocardiographic monitoring in these patients.

METHODS

A prospective multicenter study with 14 Swedish coronary care units. Patients with right bundle branch block and suspicion of acute myocardial infarction with less than 6 hours symptom duration were included. All patients were monitored with continuous vectorcardiography for 12-24 hours.

RESULTS

Seventy-nine patients were included, 43% had acute myocardial infarction. Patients with acute myocardial infarction had significantly higher initial ST-vector magnitude values (P = 0.0014) compared to patients without acute myocardial infarction. Patients with acute myocardial infarction also showed gradual regression of ST-vector magnitude over time that was not seen for patients without acute myocardial infarction (P = 0.005). ST-vector magnitude measured at the J-point differentiated best between patients with and without acute myocardial infarction. A cutoff value of 125 microV for initial ST-vector magnitude resulted in 55% sensitivity and 87% specificity for the diagnosis of acute myocardial infarction. Over time, patients with acute myocardial infarction showed greater changes in QRS-vector difference compared to patients without acute myocardial infarction (P = 0.052).

CONCLUSION

Vectorcardiographic monitoring shows good diagnostic abilities for patients with right bundle branch block and clinical suspicion of acute myocardial infarction and could be useful for continuous monitoring of these patients.

Prognostic utility of comparative methods for assessment of ST-segment resolution after primary angioplasty for acute myocardial infarction: the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial

OBJECTIVE

This study was done to assess and compare the prognostic significance of multiple methods for measuring ST-segment elevation resolution (STR) following primary percutaneous coronary intervention (PCI).

BACKGROUND

Resolution of ST-segment elevation (STE) is a powerful predictor of both infarct-related artery patency and mortality in acute myocardial infarction (AMI). Recent thrombolytic studies have suggested that simple measures of STR may be as powerful as more complex algorithms. The optimal method of assessing STR following primary PCI has not been studied.

METHODS

We analyzed 700 patients with technically adequate baseline and post-PCI electrocardiograms from the Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (CADILLAC) trial. Five methods were used to assess STR: 1) summed %STR across multiple leads (SigmaSTR); 2) %STR in the single lead with maximum baseline STE (MaxSTR); 3) absolute maximum STE before the procedure; 4) absolute maximum STE after intervention (MaxSTPost); and 5) a categorical variable based upon MaxSTPost (High Risk).

RESULTS

At 30 days, SigmaSTR, MaxSTR, and MaxSTPost all correlated strongly with mortality (p = 0.004, p = 0.005, and p < 0.0001, respectively) and the combined end point of mortality or reinfarction (p = 0.001, p = 0.001, and p < 0.0001). At one year, SigmaSTR and MaxSTPost correlated with mortality (p = 0.04, p = 0.0001), reinfarction (p = 0.02, p = 0.0015), and the combined end point (p = 0.02, p < 0.0001). By multivariate analysis, only the simpler measures of MaxSTPost and High Risk categorization independently predicted all outcomes at both time points.

CONCLUSIONS

The STR following primary PCI in AMI correlates strongly with mortality and reinfarction, independent of target vessel patency. The simple measure of the maximal residual degree of STE after primary PCI is a strong independent predictor of both survival and freedom from reinfarction at 30 days and 1 year.

[Prediction of outcome in ST elevation myocardial infarction by the extent of ST segment deviation recovery. Which method is best?]

Simple and rapid measures are needed for timely assessment of the quality of reperfusion therapy early after fibrinolysis in acute STEMI. Sum ST segment elevation resolution (sum STR) categorized into the three groups of low risk (complete ST resolution), medium risk (partial ST resolution), and high risk (no ST resolution) has become an established method to predict infarct size, left ventricular function, epicardial vessel patency, and mortality. However, measurement of the sum of ST elevation from all leads of repeated ECG's is time-consuming. For routine practice more simple measures are needed. This report summarizes recent findings on direct comparisons between different modes of evaluation of ST segment deviation recovery employed for risk stratification in large-scale mortality trials. With respect to predictive accuracy combined with simplicity, two methods were superior to the conventional model of sum STR: 1) ST segment deviation resolution in only the one ECG lead showing the maximal deviation (single lead STR), and 2) the existing ST segment deviation in the single ECG lead of maximum deviation present 90 or 180 min after start of fibrinolysis (max STE). In multivariate analyses the ST segment deviation recovery models including sum STR were significant independent predictors of short- and long-term mortality. In receiver-operating characteristic (ROC) curves for predicting mortality the analysis of single lead STR and max STE performed better than sum STR. After categorization into risk groups patients are best classified by max STE. With an ECG recorded at 90 min in 2719 patients, the proportion of patients of sum STR, single lead STR, and max STE were 40, 34, and 43% in the low risk groups, and 24, 31, and 25% in the high risk groups. Cardiac mortality rates at 30 days were 2.0, 1.2, and 1.0% in low risk versus 9.6, 10.3, and 12.8% in the high risk groups, respectively. Long-term mortality with a followup of 5 years was best predicted by max STE risk groups.

CONCLUSION

Single lead STR and max STE are very simple, inexpensive, non-invasive, and highly reliable measures which provide very strong early prognostic information. The relationship between degree of ST segment deviation recovery and subsequent mortality is remarkably consistent. Both methods perform better than sum STR in predicting mortality. They can be used for very early risk stratification and can form a basis for an individual treatment of patients after fibrinolysis for STEMI within 6 hours of symptom onset. Of the two methods max STE is even simpler to use and has better accuracy in predicting outcome.

ST-segment analyses and residual thrombi in the infarct-related artery: a report from the ASSENT PLUS ST-monitoring substudy

BACKGROUND

Evolution of the ST segment during ST-elevation myocardial infarction (STEMI) has been shown to yield more information on prognosis than widely used invasive measurements. With continuous ST monitoring, even very occasional dynamic changes can be analyzed. We have recently suggested that ST variability during the reperfusion-phase is of prognostic importance. We wanted to further investigate this and relate it to angiographic findings.

METHODS

A total of 177 patients with STEMI were examined in the ST-monitoring substudy of the ASessment of the Safety and Efficacy of a New Thrombolytic (ASSENT) PLUS trial, comparing dalteparin with heparin as adjunctive therapy to t-PA. Patients underwent 24 hours of ST monitoring. These recordings were blindly analyzed by 2 independent observers. A coronary angiogram was performed on days 4 to 7, also blindly evaluated by 2 persons.

RESULTS

Occurrence of ST re-elevations during and after the reperfusion-phase was significantly associated with residual thrombi and TIMI-flow in the infarct-related artery. Patients without any ST re-elevations showed a thrombus in only 5% of cases, as compared with 86% of patients with prolonged (lasting >30 minutes) ST re-elevations. In a multivariate comparison including baseline-data and treatment, most information on persistence of thrombi was contributed by the presence of any ST re-elevations (odds ratio, 5.8; 95% CI, 1.3-26).

CONCLUSION

ST re-elevations during the first day of an acute myocardial infarction are associated with residual thrombi in the infarct-related artery even 4 to 7 days after the STEMI.

Continuous ST-segment monitoring of patients with left bundle branch block and suspicion of acute myocardial infarction

OBJECTIVES

Patients with left bundle branch block comprise 5-9% of all patients with acute myocardial infarction. Limited data exist on the usefulness of continuous electrocardiographic monitoring of these patients. We have investigated prospectively the usefulness of real-time continuous vectorcardiography for monitoring patients with left bundle branch block and suspicion of acute myocardial infarction.

DESIGN

A prospective multi-centre study.

SETTING

Fourteen Swedish coronary care units.

SUBJECTS

Patients with left bundle branch block and suspicion of acute myocardial infarction with <6-h symptom duration were included.

MAIN OUTCOME MEASURES

All patients were monitored with continuous vectorcardiography for 12-24 h.

RESULTS

One hundred thirty-three patients were included, 47% had acute myocardial infarction. Patients with acute myocardial infarction showed a marked relative decrease in ST-vector than those without (P = 0.0002). These changes were most marked in the first 90 min. When comparing patients with acute myocardial infarction receiving thrombolytic therapy or not, those treated with thrombolytics showed more marked decline in ST-vector magnitude (P < 0.0001) and in shorter time (P = 0.0017). All patients showed STC-vector magnitude changes that were more marked in patients with acute myocardial infarction (P = 0.0002). An STC-vector magnitude cut-off value of 65 microV after 90 min of monitoring gave 54% sensitivity and 72% specificity for diagnosis of acute myocardial infarction.

CONCLUSION

Real-time continuous vectorcardiographic monitoring of patients with left bundle branch and suspicion of acute myocardial infarction shows significant differences between those with and without acute myocardial infarction and could be of use for early diagnosis and subsequent monitoring.

Single lead ST-segment recovery: a simple, reliable measure of successful fibrinolysis after acute myocardial infarction

BACKGROUND

Successful reperfusion after acute ST-elevation myocardial infarction improves prognosis. Among the different electrocardiographic markers of reperfusion, sum ST resolution is considered the hallmark of reperfusion, but is cumbersome to use.

METHODS

To assess the usefulness of a single lead ST resolution at 90 minutes after fibrinolysis compared with the sum ST resolution in predicting Thrombolysis in Myocardial Infarction (TIMI) grade 3 flow, we used prospectively collected data from the Limitation of Myocardial Injury Following Thrombolysis in Acute Myocardial Infarction (LIMIT-AMI) study. All patients had electrocardiograms recorded at presentation and 90 minutes and a coronary angiogram 90 minutes after fibrinolysis.

RESULTS

Infarction artery patency was assessed in 238 patients with 4 different ST resolution criteria: single lead ST resolution > or =50% and > or =70% and sum ST resolution > or =50% and > or =70%. The most sensitive criteria for TIMI grade 3 flow was single lead ST resolution > or =50% (sensitivity rate, 70%; specificity rate, 54%), whereas sum ST resolution > or =70% was most the specific criteria (sensitivity rate, 45%; specificity rate, 79%). The proportion of patients with TIMI grade 3 flow was similar in all 4 ST resolution groups (P =.84). Pre-discharge infarction size and ejection fraction were also similar. No single lead or sum lead measure of ST resolution was significantly associated with an increased risk of death, heart failure, or reinfarction.

CONCLUSION

We propose that single lead ST-resolution > or =50% as an optimal electrocardiographic indicator for successful reperfusion 90 minutes after fibrinolysis. This simple electrocardiographic measure should be combined with bedside clinical and hemodynamic assessment to optimize decision making after fibrinolysis.

“Mirror-lake” serial relationship of electrocardiographic and biochemical indices for the detection of reperfusion and the prediction of salvage in patients with acute myocardial infarction

BACKGROUND

Serial observations of biochemical markers in the blood and bioelectric markers on the electrocardiogram (ECG) have been used to evaluate the effectiveness of reperfusion therapy in acute myocardial infarction (AMI). This study presents a combined method for clinical use, based on the "mirror-lake" tendency of the serial changes in these markers.

METHODS

Consecutive thrombolytic-treated patients with AMI (n = 43) had ST-segment monitoring (Mortara Eli 100) and frequent serum sampling of myoglobin (MG) concentration. Their acutely predicted and finally estimated AMI sizes and myocardial salvage extents were calculated from the 12-lead standard ECG. Patients having 2 positive reperfusion indices (ST resolution at least 50%, and an increase in MG at least 2.4 fold) at 2 hours after initiation of thrombolytic therapy were considered the "complete reperfusion" group, and patients with discordant or 2 negative reperfusion indices after 2 hours of thrombolytic therapy were considered the "limited reperfusion" group.

RESULTS

Patients with complete reperfusion (n = 22) versus patients with limited reperfusion (n = 21) had +12% versus -1% myocardial salvage (P <.0001). The serial changes in the ST segment mirrored the serial changes in the MG concentration, and the rates of increase in MG correlated with the rates of resolution of the ST-segment elevation.

CONCLUSION

Myocardial salvage (measured by ECG indices) is greatest when an early increase in serum MG is "mirrored" by early resolution of ST-segment elevation.

Does 24-hour ST-segment resolution postfibrinolysis add prognostic value to a Q wave? An ASSENT 2 electrocardiographic substudy

BACKGROUND

Both ST resolution and Q-wave development postfibrinolysis provide important prognostic insights in patients with acute myocardial infarction (MI). However, the relative contributions of these 2 factors to risk assessment have not been examined prospectively.

METHODS AND RESULTS

ST resolution and Q development were evaluated 24 to 36 hours (24-36 h) postfibrinolysis in ASSENT-2: 13,100 out of 16,949 patients who had both baseline and 24-36 h electrocardiograms free of confounders (left bundle branch block, ventricular rhythm, reinfarction before 24-36 h electrocardiograms) were included in this analysis. Q-wave MI evolved in 10,466 patients (79.9%) and 2634 patients (20.1%) had non-Q-wave MI at 24-36 h postfibrinolysis. Mortality rates at 1-year were 7.0% for patients with Q-wave MI and 5.8% for non-Q-wave MI patients, respectively (P =.046). Patients with Q-wave MI versus those without were less likely to have complete ST-segment resolution (49.1% vs 59.1%) and more likely to have partial (37.1% vs 27.8%) or no resolution (13.8% vs 13.1%) at 24 to 36 hours postfibrinolysis (P <.001). Mortality rates at 1 year for Q-wave MI with complete, partial, and no resolution were 5.2%, 8.1%, and 10.1%, respectively (P <.001), and for non-Q-wave MI with complete, partial, and no resolution were 4.5%, 7.6%, and 8.0% (P =.003).

CONCLUSION

These results demonstrate the additional prognostic significance of ST-segment resolution to Q-wave development at 24 to 36 hours after fibrinolysis.

Value of the electrocardiogram in predicting left ventricular enlargement and dysfunction after myocardial infarction

To identify electrocardiographic predictors of left ventricular enlargement or persistent dysfunction following a myocardial infarction. Baseline and predischarge 12-lead electrocardiograms (ECGs) from 272 patients with anterior myocardial infarction who were enrolled in the Healing and Early Afterload Reducing Therapy trial were evaluated and related to echocardiographic data obtained at baseline and day 90. ST-segment elevation, QRS score, and number of negative T waves were assessed at both time points. The majority of patients (87%; n = 237) received reperfusion therapy. Multivariate models were used to adjust for potential confounders, including maximal creatine kinase level and ejection fraction at baseline. None of the baseline electrocardiographic variables independently predicted ventricular enlargement or recovery of function. In contrast, the sum of ST- and maximum ST-segment elevation, and the number of leads with ST-segment elevation > or =1 mm in the predischarge ECG, were independent predictors of ventricular enlargement from baseline to day 90. Each lead with ST-segment elevation > or =1 mm was associated with 3.5 mL of ventricular enlargement (95% confidence interval [CI]: 1.6 to 5.5 mL; P <0.0001). Similarly, the sum of ST-segment elevation (odds ratio [OR] = 0.78; 95% CI: 0.69 to 0.89; P <0.0001), the maximum ST-segment elevation (OR = 0.25; 95% CI: 0.13 to 0.45; P <0.0001), and the number of leads with ST-segment elevation > or =1 mm (OR = 0.58; 95% CI: 0.45 to 0.74; P <0.0001) were independently associated with a lower likelihood of recovery of function at day 90. Predischarge ECG may be a useful tool for early identification of patients at risk of ventricular enlargement and persistent dysfunction following myocardial infarction.

Predicting outcome after thrombolysis in acute myocardial infarction according to ST-segment resolution at 90 minutes: a substudy of the GUSTO-III trial. Global Use of Strategies To Open occluded coronary arteries

BACKGROUND

Resolution of ST-segment elevation after thrombolysis for acute myocardial infarction has been shown to have prognostic significance 3 hours (180 minutes) after the initiation of therapy. Whether prognostically useful information can be achieved as early as 90 minutes after thrombolysis is unknown.

METHODS

An electrocardiographic substudy of 2352 patients from the Global Use of Strategies To Open occluded coronary arteries (GUSTO-III) trial was undertaken to compare outcomes according to ST-segment resolution at 90 minutes versus 180 minutes after administration of thrombolytic therapy.

RESULTS

Of 2352 patients in the substudy, 2241 had a baseline and 90-minute electrocardiogram, and 2218 had a baseline and 180-minute ECG. Complete ST-segment resolution occurred in 44.2% of patients at 90 minutes and 56.5% of patients at 180 minutes. ST-segment resolution at both 90 and 180 minutes was associated with lower 30-day and 1-year mortality. Multivariate analysis revealed ST-segment resolution at 90 minutes to be an equally strong predictor of 30-day mortality as resolution at 180 minutes. Patients who were at particularly high risk for mortality were those aged >70 years, those who presented with Killip class >1, and those with anterior infarctions.

CONCLUSIONS

The presence of ST-segment resolution on standard 12-lead electrocardiographic monitoring 90 minutes after thrombolysis is a useful independent predictor of mortality at 30 days and 1 year. The potential for obtaining prognostic results as early as 90 minutes after thrombolysis sets a new precedent for optimum electrocardiographic monitoring times in these patients.

Time to treatment influences the impact of ST-segment resolution on one-year prognosis: insights from the assessment of the safety and efficacy of a new thrombolytic (ASSENT-2) trial

BACKGROUND

Early ST resolution after reperfusion is a prognostic indicator in acute myocardial infarction. Little information exists regarding the prognostic utility of ST resolution beyond 4 hours after fibrinolysis. Furthermore, the relation between time to treatment, ST resolution at 24 to 36 hours, and 1-year outcome has not been well studied. Accordingly, we undertook a prospective ECG substudy in the Assessment of the Safety and Efficacy of a New Thrombolytic (ASSENT-2) trial to examine this.

METHODS AND RESULTS

Patients (n=13 100) were stratified into 3 ST-resolution categories, based on baseline and 24- to 36-hour ECGs: complete resolution (>/=70%) in 6698 (51.1%) patients, partial resolution (30% to 70%) in 4610 (35.2%) patients, and no resolution (<30%) in 1792 (13.7%) patients; 1-year mortality rate was 5.1%, 8.0%, and 9.7%, respectively (P<0.001). Among patients treated <2 hours after symptom onset, 55.6% had complete ST resolution, whereas 52.1% and 43% of patients treated between 2 to 4 hours and 4 to 6 hours, respectively, had complete ST resolution (P<0.001). Within each category of ST resolution, patients treated <2 hours had lower 1-year mortality rates as compared with patients treated between 2 to 4 hours or >4 hours (3.8% versus 5.2% and 6.6%, P=0.002 in complete ST resolution; 5.7% versus 8.4% and 9.9%, P=0.001 in partial ST resolution; 7.1% versus 8.7% and 13%, P=0.006 in no resolution). The extent of ST resolution was closely and inversely correlated with 1-year mortality rates (r=-0.963, P<0.001).

CONCLUSIONS

ST resolution at 24 to 36 hours after fibrinolysis is influenced by time to treatment and inversely related to 1-year mortality rates. Time to treatment further differentiates between high- and low-risk patients and further highlights the importance of reducing time delay to initiation of fibrinolysis in acute myocardial infarction.

Extent of ST-segment deviation in a single electrocardiogram lead 90 min after thrombolysis as a predictor of medium-term mortality in acute myocardial infarction

BACKGROUND

In evolving myocardial infarction, assessment of the sum of early resolution of ST-segment elevation (sumSTR) has become an established method to predict outcome. We have found previously that mortality is predicted more accurately by the existing ST-segment deviation in the single electrocardiograph (ECG) lead with maximum deviation (maxSTE) 90 min after start of thrombolysis. This report compares the power to predict medium-term mortality by these two approaches.

METHODS

An ST-segment resolution substudy was done in conjunction with the Intravenous nPA for Treatment of Infarcting Myocardium Early (InTIME) II Study, which compared mortality in patients with acute myocardial infarction randomly assigned lanoteplase or alteplase. In 2719 patients, a 12-lead ECG was assessed at baseline and 90 min after the start of thrombolytic therapy.

FINDINGS

MaxSTE achieved a better combination of sensitivities and specificities for mortality prediction than sumSTR. The area under the receiver-operating characteristic curves for 180-day mortality prediction was 0.680 for maxSTE and 0.622 for sumSTR (difference 0.058; 95% CI 0.027-0.088). Risk groups categorised at low, medium, or high risk by maxSTE comprised 43%, 32%, and 24% of patients and those by complete, partial, or no sumSTR comprised 40%, 36%, and 24% of all patients. The 180-day mortality rates for the three maxSTE risk groups were 3.1%, 7.1%, and 16.2%, and those for the sumSTR groups were 4.8%, 8.1%, and 11.7%. The 12-month Kaplan-Meier estimates were 4.1%, 8.8%, and 18.6%, and 5.9%, 9.9%, and 13.7%, respectively.

INTERPRETATION

MaxSTE predicts early and medium-term mortality more accurately than does sumSTR. The prognosis for an individual patient can be accurately estimated simply by the ST-segment deviation present in one ECG lead recorded 90 min after thrombolysis.

ST segment resolution as a tool for assessing the efficacy of reperfusion therapy

Rapid, simple and inexpensive measures are needed to assess the efficacy of reperfusion therapy both in clinical practice and in clinical trials testing novel reperfusion regimens. In the last decade, several observations have led to a favorable reappraisal of the utility of ST segment monitoring as a simple means of assessing reperfusion in patients receiving fibrinolytic therapy for acute ST elevation myocardial infarction, and ST resolution is being used increasingly in clinical practice and in clinical research. This review focuses on four interrelated roles for ST segment monitoring: the assessment of epicardial reperfusion and the identification of candidates for rescue percutaneous coronary intervention; the evaluation of microvascular and tissue-level reperfusion; the determination of prognosis early after fibrinolytic therapy; and the use of ST segment resolution to compare different reperfusion regimens.

Clinical implications of early ST-segment variability. A report from the ASSENT 2 ST-monitoring sub-study

OBJECTIVES

Evolution of the ST-segment during acute myocardial infarction has been shown to yield more information on prognosis than invasive measurements. By continuous ST-monitoring even very occasional dynamic changes can be analysed. We have recently suggested these variations to be of prognostic importance and possibly reflect individual abilities to deal with a vascular event. We wanted to confirm these findings.

METHODS

Four hundred and forty-eight patients were included in the vectorcardiographic sub-study of the second Assessment of Safety and Efficacy of a New Thrombolytic (ASSENT 2) trial. Patients underwent 24 h of ST-monitoring. ST-trend curves were blindly analysed by two independent observers.

RESULTS

ST-variability, defined as an increase of the ST-segment shift of > or = 25 microV for 2 min or more, was found to predict death, reinfarction at 30 days or urgent revascularization. By combining variability with resolution of the ST-segment elevation we could identify a high-risk group with 9.9%, and a low-risk group with only 0.8% 30-day mortality. Hypertensive patients, suggested to have an impaired secretion of endogenous t-PA, expressed significantly more ST-variability, possibly a non-invasive marker of impaired capability of dissolving and preventing thrombi.

CONCLUSION

Small variations in ST-segment shift during the first 4 h of acute myocardial infarction predict worse outcome.

Comparison of a 60- versus 90-minute determination of ST-segment resolution after thrombolytic therapy for acute myocardial infarction. In TIME-II Investigators. Intravenous nPA for Treatment of Infarcting Myocardium Early-II

Determination of ST-segment resolution 60 minutes after the administration of thrombolytic therapy allows accurate risk stratification for mortality and congestive heart failure. Patients with complete ST resolution at 60 minutes tended to be at lower risk for 30-day mortality than patients with complete ST resolution at 90 minutes.

The use of the electrocardiogram to identify epicardial coronary and tissue reperfusion in acute myocardial infarction

The standard 12-lead electrocardiogram (ECG) gives us crucial information concerning myocardial perfusion and the success of reperfusion therapy for ST elevation acute myocardial infarction. Continuous monitoring has advantages over repeated snapshot recordings. There are four electrocardiographic markers for prediction of the perfusion status of the ischemic myocardium: (1) ST-segment measurements, (2) T-wave configuration, (3) QRS changes, and (4) reperfusion arrhythmias. Complete and stable (> or = 70%) resolution of ST-segment elevation is associated with better outcome and preservation of left ventricular function than partial (30 to 70%) or no (<30%) ST-segment resolution. Early inversion of the T waves after initiation of reperfusion therapy is another marker of myocardial reperfusion and a good prognostic sign. Using standard 12-lead ECG, dynamic changes in Q-wave number, amplitude, and width; R-wave amplitude; and S-wave appearance are detected during reperfusion therapy. However, the significance of these changes has not been clarified. Reperfusion arrhythmias, especially bradycardia and accelerated idioventricular rhythm, are detected occasionally during reperfusion therapy, but the value of reperfusion arrhythmias as a marker of coronary artery patency is still debatable. Dynamic changes in the QRS complexes, ST segments and T waves occur during reperfusion therapy and the days after. Whereas changes in ST-segment amplitude have been extensively studied, the significance of QRS-complex and T-wave changes is less clear, and especially whether changes in the QRS complex and T wave may be complementary and additive to ST-segment monitoring. It has remained unclear whether electrocardiographic signs of reperfusion and reischemia should be used for therapeutic decision making in the clinical setting.

Very early risk stratification after thrombolytic therapy with a bedside myoglobin assay and the 12-lead electrocardiogram

BACKGROUND

Available clinical criteria to estimate prognosis in patients with evolving ST-segment elevation myocardial infarction do not consider the impact of reperfusion therapy and do not incorporate measurement of baseline levels of cardiac serum markers. We evaluated the combination of a baseline myoglobin assay and early (60- to 90-minute) ST resolution for risk stratification after ST-segment elevation myocardial infarction.

METHODS

In a prospective substudy of the Intravenous nPA for Treatment of Infarcting Myocardium Early-II (InTIME-II) trial carried out in 2079 patients, a rapid qualitative assay for myoglobin was performed immediately before thrombolysis. Serial 12-lead electrocardiograms were performed at baseline and 60 to 90 minutes after thrombolysis. ST resolution was categorized as complete (>/=70%), partial (30% to <70%), or none (<30%).

RESULTS

Mortality rate at 30 days was 3.3% in the 905 patients with a negative baseline myoglobin assay versus 8.9% in the 527 patients with a positive assay (P <.0001). Mortality rate was lowest (2.4%) among the 614 patients with complete ST resolution, intermediate (4.9%) among the 512 patients with partial ST resolution, and highest (8.1%) among the 540 patients with no ST resolution (P <.0001 for trend). In a logistic regression model incorporating other baseline predictors of 30-day mortality rate, both a positive myoglobin assay (relative risk 1.98, 95% confidence interval 1.00-3.90) and ST resolution <70% (relative risk 2.86, 95% confidence interval 1.22-6.69) were independently associated with increased mortality rate. At 30 days, mortality rate was 0.4% among patients with a negative myoglobin assay and complete ST resolution, 4.8% among patients with either a positive myoglobin assay or ST resolution <70%, and 9.6% among those with both a positive myoglobin ratio and ST resolution <70% (P <.001 for trend).

CONCLUSIONS

Within 90 minutes after administering thrombolytic therapy for acute myocardial infarction, clinicians can determine the risk for death at the patient's bedside with a hand-held myoglobin assay and 2 serial 12-lead electrocardiograms. A strategy using these 2 simple, rapid, and inexpensive tests may facilitate triage after thrombolytic therapy.

Failed thrombolysis in myocardial infarction

Prompt treatment with thrombolytic therapy in acute myocardial infarction has been proven to reduce infarct size and mortality. However, reperfusion fails to occur in 30-50% of patients, either due to impaired epicardial artery flow or microvascular occlusion, with these patients experiencing a higher morbidity and mortality. We review the diagnosis and management of failed thrombolysis in acute myocardial infarction.

The use of the electrocardiogram to identify epicardial coronary and tissue reperfusion in acute myocardial infarction

The standard 12-lead ECG gives us crucial information concerning myocardial perfusion and the success of reperfusion therapy for ST-elevation acute myocardial infarction. Continuous monitoring has advantages over repeated snapshot recordings. There are four electrocardiographic markers for prediction of the perfusion status of the ischemic myocardium: 1) ST-segment measurements; 2) T-wave configuration; 3) QRS changes; and 4) reperfusion arrhythmias. Complete and stable (> or = 70%) resolution of ST-segment elevation is associated with better outcome and preservation of left ventricular function than partial (30% to 70%) or no (< 30%) ST-segment resolution. Early inversion of the T-waves after initiation of reperfusion therapy is another marker of myocardial reperfusion and a good prognostic sign. Using standard 12-lead ECG, dynamic changes in Q-wave number, amplitude and width, R-wave amplitude and S-wave appearance are detected during reperfusion therapy. However, the significance of these changes have not been clarified. Reperfusion arrhythmias, especially bradycardia and accelerated idioventricular rhythm are detected occasionally during reperfusion therapy, but the value of reperfusion arrhythmias as a marker of coronary artery patency is still debatable. Dynamic changes in the QRS complexes, ST-segments and T-waves occur during reperfusion therapy and the days after. While changes in ST-segment amplitude have been extensively studied, the significance of QRS-complex and T-wave changes are less clear, and especially whether changes in the QRS-complex and T-wave may be complementary and additive to ST-segment monitoring. It has remained unclear whether electrocardiographic signs of reperfusion and re-ischemia should be used for therapeutic decision-making in the clinical setting.

Angiographic assessment of prospectively determined non-invasive reperfusion indices in acute myocardial infarction

OBJECTIVE

To investigate the value of non-invasive reperfusion indices in acute myocardial infarction, avoiding the possible need for acute coronary angiography and subsequent angioplasty.

DESIGN

In a prospective angiographic study, seven potential ECG or clinical markers of reperfusion were analysed in 230 patients with acute myocardial infarction. In all patients two 12 lead ECGs were used: the ECG on admission and the ECG immediately before coronary angiography. Non-invasive markers of reperfusion determined just before coronary angiography were prospectively correlated to thrombolysis in myocardial infarction (TIMI) flow. Data analysis correlated these non-invasive indices with coronary flow (analysis A: TIMI 2-3 v TIMI 0-1 flow; analysis B: TIMI 3 v TIMI 0-2 flow).

RESULTS

A sudden decrease in chest pain was the most common sign of reperfusion (36%), followed by reduction in ST segment elevation by >/= 50% (30%), and the development of a terminal negative T wave (20%) in the lead with the highest ST segment elevation. Reduction in ST segment elevation by > or = 50% and the appearance of an accelerated idioventricular rhythm (AIVR) had the highest positive predictive value for reperfusion. For analyses A and B, the positive predictive values were 85% and 66% for resolution of ST segment elevation, and 94% and 59% for AIVR, respectively. The presence of three or more non-invasive markers of reperfusion predicted TIMI 3 flow accurately in 80% of cases.

CONCLUSIONS

The prospective use of non-invasive indices of reperfusion is simple, practical, and can be of value in assessing coronary patency in patients admitted with acute myocardial infarction. Using these indices, discrimination between TIMI 0-1 and TIMI 2-3 flow can be made with good accuracy. However, TIMI 3 flow cannot be determined reliably. The use of such non-invasive indices depends on the goal of reperfusion.

ST-Segment recovery adds to the assessment of TIMI 2 and 3 flow in predicting infarct wall motion after thrombolytic therapy

BACKGROUND

Early resolution of ST-segment elevation (ST-segment recovery) is associated with an improved outcome after infarction. Whether this relation is present in patients with Thrombolysis In Myocardial Infarction (TIMI) grade 2 or 3 flow (ie, patent) infarct-related arteries is not known.

METHODS AND RESULTS

To examine the associations between time to achieve stable 50% ST-segment recovery assessed by continuous ECG monitoring, infarct artery flow, and infarct zone wall motion (at 48 hours), we studied 134 patients who underwent angiography at 99 (interquartile range 92 to 110) minutes after commencing streptokinase, initiated within 12 hours of onset of symptoms of myocardial infarction. Patients with TIMI 2 or 3 flow who failed to achieve early stable ST-segment recovery (50% ST-segment recovery sustained for > or 4 hours with <100 microV change in the peak lead) by 60 or 90 minutes had a higher fraction of chords in the infarct zone >2 SD below normal wall motion (TIMI 2: 55.5% vs 15.3%, P=0.006; and 56.5% vs 26.8%, P=0.01, respectively; and TIMI 3: 48.8% vs 28.3%, P=0.07; and 51.8% vs 29.9%, P=0.03, respectively). Time to stable ST-segment recovery was a multivariate predictor of infarct zone wall motion (P=0.04) independent of TIMI flow grade and the time from symptom onset to streptokinase therapy.

CONCLUSIONS

In patients with TIMI 2 or 3 flow in infarct-related artery, early stable ST-segment recovery is associated with improved infarct zone wall motion at 48 hours. ST-segment recovery may provide additional information about the degree of myocyte reperfusion achieved in patients with a patent epicardial infarct-related artery after thrombolytic therapy.

ST-segment resolution and infarct-related artery patency and flow after thrombolytic therapy. Thrombolysis in Myocardial Infarction (TIMI) 14 investigators

Because patients who fail to achieve reperfusion after thrombolytic therapy remain at high risk for morbidity and mortality, noninvasive measures of infarct-related artery (IRA) patency are needed to identify candidates for rescue interventions. We prospectively studied 444 patients from the Thrombolysis In Myocardial Infarction (TIMI) 14 trial with interpretable baseline and 90 minute 12-lead electrocardiograms. The percent resolution of ST-segment deviation from baseline to 90 minutes was compared with 90-minute IRA TIMI flow grade, as determined in an angiographic core laboratory. Patients with complete (> or = 70%) ST resolution (n = 208; 47%) had a patency (TIMI 2 or 3 flow) rate of 94%, a TIMI 3 flow rate of 79%, and a 30-day mortality rate of 1.0%. Patients with partial (30% to 70%) or no (< or = 30%) ST resolution had significantly lower rates of patency (72% and 68%; p < 0.0001 vs complete ST resolution) and TIMI 3 flow (50% and 44%; p < 0.0001 vs complete ST resolution), and higher 30-day mortality (4.2% and 5.9%; p = 0.01 vs complete ST resolution). With use of electrocardiographic criteria alone, approximately 50% of patients can be classified as having a high (94%) probability of IRA patency and a very low risk for mortality. Angiography to determine patency of the IRA may be unnecessary in these patients. In patients without complete (> or = 70%) ST resolution, the IRA is still likely to be patent, and additional information from clinical variables or serum markers may help to identify candidates for coronary angiography. Patients with persistent ST elevation despite a patent IRA are at increased risk for mortality, likely due to extensive microvascular and tissue injury.

Abciximab improves both epicardial flow and myocardial reperfusion in ST-elevation myocardial infarction. Observations from the TIMI 14 trial

BACKGROUND

In the presence of ST-elevation myocardial infarction, patients with successful epicardial reperfusion (TIMI 3 flow) but persistent ST elevation on a 12-lead ECG are at high risk for subsequent death and left ventricular dysfunction. In the TIMI 14 trial, a dose-ranging angiographic study, combined therapy with abciximab plus reduced-dose tPA enhanced the speed and efficacy of epicardial reperfusion. We determined whether the combination of abciximab plus reduced-dose tPA provided additional benefit in terms of myocardial reperfusion, as evidenced by greater resolution of ST elevation.

METHODS AND RESULTS

All 346 patients with interpretable baseline and 90-minute ECGs, treated with either tPA alone or abciximab plus reduced-dose tPA (combination therapy), were included. Patients receiving combination therapy (n=221) had a 59% rate of complete (>/=70%) ST resolution at 90 minutes versus 37% in those treated with tPA alone (n=125) (P<0.0001). When the analysis was limited to patients with TIMI 3 flow, patients treated with combination therapy (n=151) remained significantly more likely to achieve complete ST resolution than those receiving tPA alone (n=80) (69% versus 44%; P=0.0002).

CONCLUSIONS

Combination therapy with abciximab and reduced-dose tPA improves myocardial (microvascular) reperfusion, as reflected in greater ST-segment resolution, in addition to epicardial flow. This finding may translate into improved clinical outcomes by enhancing myocardial salvage.

Clinical Utility of Electrocardiographic ST-Segment Area for Predicting Unsatisfactory Outcomes Following Thrombolytic Therapy

The bedside surface 12-lead electrocardiogram is a mainstay in the early diagnostic evaluation of patients with suspected acute myocardial infarction. The presence of ST-segment elevation exceeding 1.0 mm in two or more anatomically associated leads is a reliable marker of myocardial injury and, when considered along with concomitant ST-segment depression, reflects the extent of myocardial injury. Mounting evidence also suggests that prolonged repolarization is a marker of injury and predicts the likelihood of malignant ventricular arrhythmias. We questioned whether a measure of both ST-segment duration and deviation (ST-deviation area) would offer additional prognostic information. Methods/Results: Admission electrocardiograms from 200 consecutive patients with ischemic chest pain accompanied by ST-segment elevation in whom thrombolytic therapy was given within 6 hours from symptom onset were analyzed. The sum of ST-segment elevation (Sigma ST elevation) and ST-segment deviation (Sigma ST deviation) were calculated, as was the sum of ST-segment deviation area (Sigma ST deviation area). All ST measurements were performed 60 msec after the J point. Computerized planimetry was used to calculate ST-segment area. Sigma ST deviation and Sigma ST deviation area remained constant over time. Patients with large deviations (Sigma ST elevation > 20 mm (odds ratio 2.14, p = 0.02) and Sigma ST deviation area > 150 (odds ratio 1.92, p = 0.02) had a higher incidence of in-hospital unsatisfactory clinical outcome (defined as death, congestive heart failure, cardiogenic shock, recurrent myocardial infarction, or the need for coronary revascularization). These relationships were present for both inferior and anterior infarctions. Sigma ST deviation area correlated closely with Sigma ST elevation (r = 0.92; p = 0.0001) and significantly but much less strongly with the sum of Q waves (r = 0.18; p = 0.01). By univariate analysis, only site of infarction (p = 0.01), Sigma ST deviation area (p = 0.04), and the sum of Q waves (p = 0.005) were identified as predictors of a poor clinical outcome. The sum of Q waves was identified by multivariate analysis as the best independent predictor of an unsatisfactory clinical outcome. Conclusions: A clinician's ability to provide optimal care is influenced strongly by the availability of diagnostic and prognostic information. In the evaluation of patients with acute myocardial infarction, ST-segment deviation area derived from the admission surface electrocardiogram can be used to risk-stratify patients. The full clinical potential of this measure is unknown and will require further evaluation.